The independent filmmaker whose hidden-camera videos prompted the firing of four ACORN workers is demanding an apology from ACORN for calling his work a fabricated "scam" and daring the activist group to take legal action against him.

"Bring it on," filmmaker James O'Keefe said Sunday on FOX News.

That was after ACORN lashed out at O'Keefe, who with his friend Hannah Giles posed as a pimp and prostitute looking to evade the IRS and apply for an illegal housing loan for a brothel. The sting operation caught four ACORN workers in the Baltimore and Washington, D.C., offices appearing to offer their help.

Those workers were subsequently fired, and the U.S. Census Bureau severed ties with ACORN in the wake of the controversy. But ACORN chief organizer Bertha Lewis issued a written statement Saturday saying that while she cannot defend the actions of the workers who were terminated, O'Keefe may have committed a "felony" with his operation. She also threatened legal action against FOX News, which aired the videos but did not produce them.

"It is clear that the videos are doctored, edited, and in no way the result of the fabricated story being portrayed by conservative activist 'filmmaker' O'Keefe and his partner in crime. And, in fact, a crime it was -- our lawyers believe a felony -- and we will be taking legal action against Fox and their co-conspirators," she said.

In an interview with FOX News senior correspondent Eric Shawn, O'Keefe said he wants an apology from those media outlets "covering for ACORN" as well as from ACORN itself. He said he doubts ACORN will file suit.

"They don't have any leg to stand on, so they're saying I dubbed in my voice which is completely absurd," he said. "When the truth comes out in the end, they're going to be apologizing to us."

O'Keefe said he was "just trying to hold these organizations accountable."

Lewis said in her statement that O'Keefe's "scam" was attempted in several other cities but had "failed for months."

O'Keefe declined to comment on the allegedly unsuccessful attempts, but said it's a "lie" to claim that any ACORN offices "kicked us out."